1. Field of the Invention
The present invention relates to railway freight cars and in particular to freight car door track structures.
2. Description of the Prior Art
During cargo loading and unloading operations, freight car door track structures are continually bumped or jarred by the cargo as well as the cargo loading or material handling equipment. As a result the door track may become bent or dented such that it obstructs opening and closing of the car door.
The prior art door track structures are exemplified by U.S. Pat. Nos. 2,415,731; 2,447,846; and 2,824,339. U.S. Pat. Nos. 2,415,731 and 2,447,846 disclose door track structures intended to prevent the entry of direct or reflected light and foreign matter upwardly into the car through the door openings; and, U.S. Pat. No. 2,824,339 shows a sliding box car door carried on a door track supported from a side sill reinforcement through a series of longitudinally spaced gusset plates. None, however, disclose the novel door track construction of the present invention which essentially eliminates obstructive distortion or loosening of the door track as well as providing a light and weather shielding structure which is easily fabricated and inexpensive to repair or replace during the service life of the car.